A longitudinal study investigated maternal social support and its relationship to mother/child stress, the amount of stimulation provided the child, and the child's cognitive development. The data presented here represent the 18 to 24 month follow-up on a subset of families studied in 1981 and 1982 concerning current maternal social support and indices of mother/child stress, home stimulation, and the child's cognitive development. Participants were 38 mothers with a mean age of 23.7 years and their 18- to 24-month-old children. Measures administered included the Maternal Social Support Index, the Parental Stress Index, the Inventory of Home Stimulation, the Bayley Scales of Infant Development, and a demographic questionnaire. Results indicated that maternal social support is an important predictor of perceived mother/child stress. Further, the inclusion of maternal social support levels can meaningfully improve the predictability of the level of home stimulation above and beyond socioeconomic status data alone. Results suggest that the use of punishment and restriction increases as maternal social support decreases. Higher levels of mother/child stress are associated with a lack of stimulating play materials. No predictors of infant development were found. (RH)